pub fn odd_fibnacci_sum(threshold: u32) -> u32 {
    let mut sum = 1;
    let mut a = 0;
    let mut b = 1;
    let mut c = a + b;
    while c <= threshold {
        if c % 2 == 1 {
            sum += c;
        }

        a = b;

        b = c;
        c = a + b;
    }
    sum
}
